The generator matrix

 1  0  1  1  6  1  1  1  6  1  1  4  1  1 10  1  2  1  8  1  1
 0  1  1  6  1 11 13  4  1  2 15  1  4  1  1  6 14  7  1  9  3
 0  0  2  0  8  4 12 10  6 10  6 10 14  6  2 14  2  2 12  0 12
 0  0  0  8  8  0  8  0  8  8  8  0  0  0  8  0  0  0  8  0  8

generates a code of length 21 over Z16 who´s minimum homogenous weight is 18.

Homogenous weight enumerator: w(x)=1x^0+256x^18+380x^19+1066x^20+800x^21+984x^22+336x^23+201x^24+16x^25+48x^26+4x^27+4x^28

The gray image is a code over GF(2) with n=168, k=12 and d=72.
This code was found by Heurico 1.16 in 0.0762 seconds.